Process for cleaning soiled hydrophobic polyamide and polyester fabrics

ABSTRACT

1. A PROCESS OF CLEANING SOILED HYDROPHOBIC POLYAMIDE OR POLYESTER SUBSTRATES AND SIMULTANEOUSLY IMPARTING A SOIL REPELLENT AND ANTI-STATIC FINISH THERETO COMPRISING TREATING SAID SUBSTRATES WITH A SOLUTION OF A POLYMERIC ANHYDRIDE SELECTED FROM THE GROUP CONSISTING OF POLY(VINYL METHYL ETHER/MALEIC ANHYDRIDE), POLY(MALEIC ANHYDRIDE) AND POLY(ETHYLENE/MALEIC ANHYDRIDE) IN A SUBSTANTIALLY WATERFREE, NON-AQUEOUS, SOLVENT, SAID SOLVENT BEING FREE OF ACTIVE HYDROGEN ATOMS AND DRYING THE TREATED SUBSTRATES.

United States Patent O 3,843,388 PROCESS FOR CLEANING SOILED HYDROPHOBIC POLYAMIDE AND POLYESTER FABRICS Vincent Paul Heuring, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio No Drawing. Continuation-impart of abandoned applica tion Ser. No. 885,360, Dec. 15, 1969. This application Aug. 11, 1972, Ser. No. 280,009

Int. Cl. B44d 1/02 US. Cl. 117-66 4 Claims ABSTRACT OF THE DISCLOSURE A non-aqueous process of cleaning soiled hydrophobic polyamide and polyester substrates and simultaneously imparting to said substrate a soil-repellent finish and an anti-static finish which comprises treating said soiled substrates with a non-aqueous solution of a polymeric anhydride selected from the group consisting of poly(vinyl methyl ether/maleic anhydride), poly(maleic anhydride) and poly(ethylene/maleic anhydride), and a substantially water-free, non-aqueous solvent which is free of active hydrogen atoms.

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of eopending application Ser. No. 885,360, filed Dec. 15, 1969, now abandoned.

BACKGROUND OF THE INVENTION Polyamide (or nylon) and polyester fabrics have found wide acceptance as materials for clothing and household garments. Unfortunately, these materials are hydrophobic in nature and resist cleaning by ordinary washing and cleaning processes which employ Water. The tendency of synthetic hydrophobic fabrics to become off-white (graying, yellowing, etc.) is well known. No overall satisfactory cleaning process has been discovered to offset this tendency towards discoloration.

A variety of processes have been disclosed in the art which assertedly provide hydrophobic fabric surfaces with surface coatings which are more easily cleaned by ordinary dry-cleaning solvents. For example, U.S. Pat. 3,297,- 786 discloses a metal-catalyzed process for affixing monomeric materials to fabric surfaces to provide ease of cleaning. However, all prior art processes employ catalysts, high temperature curing procedures, etc., to effect good fabric coating with such soil repellent finishes.

It has now been discovered that soiled hydrophobic polyamide and polyester substrates can be coated with a soil release polymer in an effective manner Without the use of catalysts by contacting said soiled substrates with a non-aqueous solution of certain polymeric anhydrides. In addition to providing a soil repellent finish on the substrates, the polymeric anhydrides unexpectedly enhance the cleansing action of the non-aqueous solvent system. That is to say, it has now been found that the polymeric anhydrides employed herein perform a detergent function when dissolved in non-aqueous dry-cleaning solvents. Furthermore, the polymeric anhydrides herein can be advantageously employed in combination with certain phosphate esters such as those disclosed in Product Licensing Index, June 1972, No. 9856.

It is an object of this invention to provide novel detergents for use in non-aqueous dry-cleaning processes. It is a further object herein to provide dry-cleaning systems which concurrently cleanse soiled fabrics and afiix a soil repellent and anti-static finish thereto. These and other objects are obtained herein as will be seen from the following disclosure.

SUMMARY OF THE INVENTION The present invention encompasses non-aqueous processes for cleaning soiled hydrophobic polyamide and polyester substrates while simultaneously imparting to said substrates a soil-repellent and anti-static finish comprising contacting said soiled substrates with a substantially non-aqueous solution comprising from about 0.01% to about 10%, preferably 1% to 3%, by weight of a polymeric anhydride selected from po'ly(vinyl methyl ether/ maleic anhydride), p0ly(maleic anhydride) and poly(ethylene/maleic anhydride) the balance of said solution comprising a substantially non-aqueous organic dry-cleaning solvent, as disclosed below. The treating step comprises Washing said substrates in the substantially non-aqueous washing solution.

The invention also encompasses substantially non-aqueous dry-cleaning compositions comprising: (1) from about 0.01% to about 10%, preferably 1% to 3%, by weight of a polymeric anhydride of the type set forth above; (2) from about 0.01% to about 4%, preferably 0.005% to about 2%, by weight of an alkoxylated phosphate ester surfactant of the type disclosed hereinafter; and (3) the balance of said composition comprising a substantially water-free, non-aqueous dry-cleaning solvent capable of co-dissolving said polymeric anhydride and phosphate ester.

DETAILED DESCRIPTION OF THE INVENTION The discovery on which the present invention is based is that certain polymeric anhydrides dissolved in a substantially non-aqueous solution wherein a major proportion of the anhydride bonds are intact are capable of dislodging soil attached to a hydrophobic substrate and releasing it therefrom while concurrently attaching the polymer to the fabric surface to provide a soil repellent and anti-static finish. While the exact mechanism for this dynamic release of soil is not fully understood, it is believed that the polymeric anhydride chemically reacts with the amide, amine, or hydroxyl groups in the polyamide and polyester substrates and thereby releases soil which may be attached in proximity to these reaction sites. As a result, the polymeric anhydride becomes permanently chemically bonded to the substrate and unexpectedly imparts to the substrate a soil-repellent and anti-static finish. The molecular arrangement of the bonded anhydride is that it is bound to the substrate either through imide, amide, or ester molecular groups.

Furthermore, the polymeric anhydrides herein can be employed conjointly with certain well-known phosphate ester dry-cleaning detergents which provide an added increment of cleaning. Surprisingly, the conjoint use of the polymeric anhydride and the phosphate ester does not interfere with the deposition of the soil repellent finish on the fabric surface.

The preferred polymeric anhydride used herein is poly (vinyl methyl ether/maleic anhydride) having a specific viscosity in the range of 0.1 to 0.5, as determined on a solution of 1 gm. of the polymer in ml. of methyl ethyl ketone (MEK) at 25 C. These types of compounds are manufactured by General Aniline and Film Company as Gantrez AN-l19, AN139, and AN-169.

Other examples of suitable polymeric anhydrides are poly()maleic anhydride) and poly'lethylene/maleic anhydride The solution of the polymeric anhydride can be prepared by dissolving it in a substantially non-aqueous organic solvent which has a cohesive energy density in the range of 9 to 14, and especially 9 to 10, and which does not contain active hydrogen atoms, such as -NH -NH, alcoholic-OH groups, and the like. Examples of such solvents are the common, halogenated hydrocarbyl dry-cleaning solvents such as perchloroethylene, perchloro propane, 1,1,4,4-tetrachlorobutane, carbon tetrachloride, and the like, as Well as solvents such as acetone, dioxane and Stoddard solvent.

The proportion of polymeric anhydride in the substantially non-aqueous solvent can range from .01 to 10% by weight of the solvent, preferably 1% to 5% by weight and the balance 90% to 99.99% solvent. Traces of water can be tolerated by the system provided the amount of water present does not hydrolyze more than about 20% of the anhydride linkages in the polymers. Tolerable mole ratios of water-to-anhydride bonds in the polymers are in the range from 0.01:1 to about 02:1, and are preferably less than 01:1.

The preferred polymeric anhydride is poly(vinyl methyl ether/maleic anhydride) and the preferred solvents herein are acetone, perchloroethylene, and Stoddard solvent.

The following example illustrates the use of the polymeric anhydride herein to simultaneously cleanse fabrics and attach a soil repellent, anti-static finish thereto.

EXAMPLE I Nylon cloths, 2 inches square, were soiled by Washing them in 1 liter of an aqueous solution containing a heavyduty detergent composition and a synthetic soil for 60 minutes at 120 F., pH 10, 7 grains/gallon hard water. The detergent compositions (used at a concentration of 0.075%) consisted of 20% sodium dodecylbenzene sulfonate, 60% sodium tripolyphosphate, and 20% sodium sulfate. The synthetic soil (used at a concentration of 0.022%) was composed of a mixture of one part air conditioner filter dirt which had been previously extracted with chloroform/methanol azeotrope and dried, and parts of a 1:1:1 mixture of light mineral oil, olive oil, and oleic acid. These ingredients were dispersed in the water in a Waring Blender before use.

A nylon cloth soiled by this procedure was then immersed in a flask containing 100 ml. of acetone and shaken for 10 minutes. Another cloth was immersed in the same volume of a 2% solution of poly(vinyl methyl ether/ maleic anhydride) in acetone and shaken for 10 minutes. B'oth cloths were allowed to dry, and each was then rinsed twice in distilled water. They were again allowed to dry, and were then soaked for several hours in distilled water. After drying, the fabrics were graded using the L scale (lightness) of a Hunter Color Difference Meter. The recovery of fabric lightness was calculated from the equation Percent recovery: L LB X 100 where L is the original lightness grade of the fabric before soil- L is the lightness grade after soiling; and

L is the lightness grade after the cleaning procedure.

The pure acetone treatment afforded only a 24% lightness recovery while the treatment embodying the present invention (anhydride-t-acetone) afforded a fabric lightness recovery of 70%. This was a totally unexpected improvement in cleaning. Moreover, the nylon fabric treated with the anhydride-l-acetone had imparted to it a soil repellent and anti-static finish.

In the foregoing procedure, the acetone is replaced by an equivalent amount of carbon tetrachloride and perchloroethylene, respectively, and equivalent results are secured in that improved fabric cleansing is achieved while a soil repellent finish is deposited on the fabric.

In the foregoing procedure, the poly(vinyl methyl ether/ maleic anhydride) is replaced by an equivalent amount of poly(maleic anhydride) and poly(ethylene/ maleic anhydride), respectively, and equivalent cleansing and fabric finishing results are secured.

As noted hereinabove, the polymeric anhydrides can be employed in combination with certain phosphate esters in dry-cleaning solvents to provide improved dry-cleaning compositions and methods. The phosphate esters useful herein are those compounds more fully described in U.S. Pat. 3,352,790, incorporated herein by reference. These phosphate esters can be broadly described as the condensation product of certain alkylene oxide substituted nonionic surfactants with P 0 or POCl and have the general formulae:

and

wherein R is a reactive hydrogen compound such as nonyl phenol, R is hydrogen, lower alkyl such as methyl, ethyl, etc., X is hydrogen, an alkali metal, ammonium, etc., and n is an integer of from about 2 to about 20.

The alkoxylated phosphate esters useful herein are commercially available under the trademark designation, Gafac, from General Aniline and Film Corporation. Preferred alkoxylated phosphate esters useful herein include:

Gafac RM 510.Reaction product of an ethoxylated dialkyl phenol and P 0 wherein the reaction product contains about 51% by weight ethoxy groups.

Gafac RS 510.Reaction product of an ethoxylated fatty alcohol and P 0 wherein the reaction product contains about 51% by weight ethoxy groups.

Gafac RE 710.Reaction product of an ethoxylated alkyl phenol and P 0 wherein the reaction product contains about 71% by weight ethoxy groups.

Gafac RM 710.Same as RM 510 except that the percent by weight of ethoxy groups is about 71%.

Gafac PE 510.Reaction product of an ethoxylated alkyl phenol and POCl wherein the reaction product contains about 51% by weight ethoxy groups.

The following example illustrates dry-cleaning compositions comprising the alkoxylated phosphate esters, the polymeric anhydrides and a substantially water-free organic dry-cleaning solvent.

EXAMPLE II Ingredient: Percent (wt.) Gafac RM 710 0.3 Poly(vinyl methyl ether/maleic anhydride) 1.0 Perchloroethylene 1 Balance 1 Containing not more than 0.01% water, by weight.

The dry-cleaning composition is prepared by admixing the above ingredients in the proportions noted until the Gafac RM 710 and anhydride polymer are completely dissolved.

Eight pounds of soiled polyester fabrics are immersed in eight gallons of the composition of Example II and agitated for five minutes. The fabrics are removed and dried at room temperature. Substantially all the soil is removed by this procedure and the fabric is coated with a soil repellent, anti-static finish.

Soiled nylon fabrics are cleansed in the solution described in Example II, above, and are concurrently coated with a soil repellent, anti-static polymeric coating provided by the poly(vinyl methyl ether/maleic anhydride).

In the foregoing composition, the Gafac RM 710 is replaced by an equivalent amount of Gafac RM 510, Gafac RS 510, Gafac RE 710 and Gafac RE 510, respectively, and equivalent results are secured.

In the foregoing composition, the poly(vinyl methyl ether/maleic anhydride) is replaced by an equivalent amount of poly(maleic anhydride) and poly(ethylene/ maleic anhydride), respectively, and equivalent dry-cleaning compositions are secured.

The following example illustrates an industrial drycleaning composition containing a minimal amount of water which is suitable for cleansing soiled work clothes while providing a soil repellent finish.

EXAMPLE III Ingredient: Percent (wt.) Gafac RE 710 1.0 Poly(vinyl methyl ether/maleic anhydride) 2.0 Water 0.1 Stoddard solvent (flash pt. 140 F.) Balance The above composition is prepared by blending the foregoing ingredients in the recited amounts until a homogeneous solution is obtained. The composition is used at arate of 100 lbs. per 25 lbs. soiled rough work clothes (polyester and polyester/cotton blends) in a commercial laundering apparatus. Clothes laundered in standard fashion using the composition of Example III are provided with a soil repellent, anti-static finish.

In the foregoing composition the Stoddard solvent is replaced by an equivalent amount of the following commercial dry-cleaning solvents, respectively, with equivalent results:

Trichlorotrifiuoroethane Naphtha Trichloroethylene Tetrachloroethylene Perchloroethylene Carbon tetrachloride Stoddard solvent, flash point 100 F.

It is to be recognized that the substantially non-aqueous dry-cleaning processes and compositions herein can contain additional, common dry-cleaning adjuvants such as various moth-proofing agents, soil suspending agents, etc., commonly found in dry-cleaning baths.

The treatment times employed in the dry-cleaning processes herein can range from about 2 minutes to about 30 minutes, depending on the soil levels in the fabrics being cleansed. Temperatures of from about 50 F. to about 110 F. can be employed, and this is limited only by the boiling points of the non-aqueous solvents used.

What is claimed is:

1. A process of cleaning soiled hydrophobic polyamide or polyester substrates and simultaneously imparting a soil repellent and anti-static finish thereto comprising treating said substrates with a solution of a polymeric anhydride selected from the group consisting of poly(vinyl methyl ether/maleic anhydride), poly(maleic Y 'anhydride) and poly(ethylene/maleic anhydride) in a substantially waterfree, non-aqueous, solvent, said solvent being free of active hydrogen atoms and drying the treated substrates.

2. A process according to Claim 1 wherein the solvent is a member selected from the group consisting of trichlorotrifluoroethane, naphtha, trichloro'ethylene, tetrachloroe thylene, perchloroethylene, carbon tetrachloride, Stoddard solvent and acetone. 3

3. A process according to Claim 1 wherein the polymeric anhydride is poly(vinyl methyl ether/maleic anhydride) and the solvent is a member selected from the group consisting of acetone, perchloroethylene and Stoddard solvent.

4. A process for cleansing soiled hydrophobic polyamide or polyester fabrics and simultaneously affixing a soil repellent and anti-static finish thereto comprising treating said fabrics with a solution comprising: (1) from about 0.0l% to about 10% by weight ofa polymeric an hydride selected from the group consisting of poly(vinyl methyl ether/maleic anhydride), poly(maleic anhydride) and poly(ethylene/maleic anhydride); '(2) from about 0.01% to about 4% by weight of an alkoxylated phosphate ester; and (3) the balance of said solution comprising a substantially water-free, non-aqueous dry-cleaning solvent which is'free from active hydrogen atoms, and drying the treated fabrics.

References Cited UNITED STATES PATENTS 2,275,593 3/1942 Muskat et al. 8l42 X 2,475,418 7/1949 Aitchison -a- 8-142 3,404,943 10/1968 Morris 8--142 X WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner US. Cl. X.R.

117-13s.s F, 138.8 N, 139.5 R, 161UZ 

1. A PROCESS OF CLEANING SOILED HYDROPHOBIC POLYAMIDE OR POLYESTER SUBSTRATES AND SIMULTANEOUSLY IMPARTING A SOIL REPELLENT AND ANTI-STATIC FINISH THERETO COMPRISING TREATING SAID SUBSTRATES WITH A SOLUTION OF A POLYMERIC ANHYDRIDE SELECTED FROM THE GROUP CONSISTING OF POLY(VINYL METHYL ETHER/MALEIC ANHYDRIDE), POLY(MALEIC ANHYDRIDE) AND POLY(ETHYLENE/MALEIC ANHYDRIDE) IN A SUBSTANTIALLY WATERFREE, NON-AQUEOUS, SOLVENT, SAID SOLVENT BEING FREE OF ACTIVE HYDROGEN ATOMS AND DRYING THE TREATED SUBSTRATES. 